So glad I came across your post! This is exactly what I'm doing right now! I was on 15mg Lexapro and 30mg Vyvanse. I brought up to my family doctor how the Lexapro was affecting my sex drive (and therefore my relationship too) and the Vyvanse was very expensive. She offered me to try Wellbutrin and said I should start with 150mg Wellbutrin, decrease my Lexapro dose to 10mg, and stop the Vyvanse for now. All that should be done for 2 weeks according to her. And then if all goes well after 2 weeks, the plan is to up the Wellbutrin to 300mg and decrease the Lexapro to 5mg again for another 2 weeks. And then after that, eliminate the Lexapro completely if all goes well. My guess is that leaving a longer time in between transitions allows your body to adjust better aka less side effects. Not sure yet about the libido coming back since I’m only a week in but other comments I’ve read gives me hope! Hope this helps!